1. be based only on household income and social status.
2. It should not affect admissions but should instead provide additional financial and educational resources. People from high socioeconomic backgrounds receive more coaching at home and elsewhere.
At the MD level, this type of preference implies it is fair to assume that Black and Hispanic doctors graduating from Yale are less competent. I have a friend who is an MD in Nepal where it's the opposite. High socioeconomic status allows students to enter medical school with very low scores due to corruption. There it is fair to assume that a doctor from a poor family or a lower caste is more competent.